Method of manufacturing belts



Aug 22, 1933. R. CARTER ET AL 1,924,083

METHOD OF MANUFACTURING BELTS Original Filed May 22. 1930 gwue'n tozEaqmond S.Car*er 3: Harohi G. DKJQ Patented Aug. 22, 1933 UNITED STATESMETHOD OF MANUFACTURING BELTS Raymond 8. Carter and Harold G. Dick,Akron,

Ohio, assignors to The Goodyear Tire & Rubber Company, Akron, Ohio, aCorporation of Ohio Original application May 22, 1930, Serial No.

454,596. Divided and this application June 6,. 1931. Serial No. 542,539

5 Claims.

This invention relates generally to endless rubber belts, and it hasparticular relation to a method for making a belt of the so-called V- atype.

An object of the invention is to provide a novel and practical method ofmanufacturing an endless belt particularly of the V-type, by means ofwhich the belt will be provided with an endless tensile member.

Another object of the invention is to provide a method of manufacturingendless belts wherein the cores of a plurality of belts are manufacturedsimultaneously and. each is provided with a helically arranged endlesstensile member.

Another object of the invention is to provide a method for making arubber belt which will be relatively soft adjacent its inner peripheralsurface, in order to avoid excessive wear of the inner comer portions ofthe belt, and deteriorating stresses in such portion of the belt. I

At the present time V belts are employed as standard equipment inconjunction with motor vehicles, for driving fan belt pulleys. Since afan belt pulley, and a pulley on the engine shaft about which the beltis trained ordinarily are small in diameter, the belt in moving aroundthe pulley is subject to considerable flexing. Particularly, the innerportion of the belt in moving about the pulleys is subjected to forceswhich tend to compress it, whereas the outer portion of the latter issubjected to forces which tend to elongate it. As a result, internal andopposing stresses are set up in the belt which tend to separate thecomponent parts thereof and frequently early failure of the belt occursbecause of such separation.

Heretofore, V-belts have been manufactured by winding strips ofrubberand cord fabric about an annular support until a core of desiredthickness was obtained and then covering the core with woven fabric. Insuch constructions, several layers of cord fabric were provided, eitheras a result of winding a single layer of cord fabric several times aboutthe support, or else winding several layers of such fabric about thesupport and circumferentially spacing the laps of the respective layers.It was intended that the cord fabric should comprise the loadtransmitting portion of the belt.

and separation of such layers, chafing of the cords in adjacent layersand deterioration of the belt by reason of excessive heat generated as aresult of frictional engagement of component parts of thecompression'layer, caused early failure of the belt. Not all of thecauses of the failure of such belts are known at present, and it ispossible that the reasons for such failure may be changed by laterdiscoveries. However, development work has satisfactorily establishedthat the belt provided by this invention has increased the life thereofto a surprising degree.

This invention effectively obviates the disadvantages heretoforeenumerated with respect to Vbelts, by providing tensile members in thebelt at the neutral plane only, thereby avoiding the use of tensilemembers on the outer and inner sides of the neutral plane. Inwardly ofthe tensile member relatively soft and easily compressible material isprovided, and the parts are so arranged, that considerable adhesion issecured between such material and the tensile member. outwardly of theneutral plane, the belt comprises material which can be elongated orstretched easily. Practically no stresses are set up in the belt duringits operation over small pulleys which tend to separate the inner andouter parts of the belt from the tensile member defining the neutralplane of the belt, because the material is well adapted to absorb thestresses on opposite sides of such plane.

The invention also contemplates the practice of a novel method ofmanufacturing belts which comprises winding flexible material such asrubber and woven fabric about a collapsible drum, and thereafter windinga cord helically about the latter. Then a thin layer of rubber isapplied to the cord, the assembled band is out into narrow annularcores, and each of the latter covered with woven fabric having itsthreads extending obliquely to the length of the belt. It is apparentthat in each of the cores a single cord constituting in effect anendless tensile member comprises the load transmitting part of the beltand, consequently, laps in the load transmitting portion of the belt areavoided. Moreover, it is to be noted that the helical convolutions ofcord coincide with the neutral plane of the belt.

For a better understanding of the invention, reference may now be had tothe accompanying drawing, forming a part of this specification in which:

Fig. 1 is a plan view of an apparatus em-' ployed for assembling anannular band of belt material, and subsequently cutting it into narrowannular cores;

Fig. 2 is a fragmentaryelevational view of a machine employed forapplying a woven fabric cover to each of the belt cores manufactured bythe apparatus shown by Fig. 1;

Fig. 3 is across-sectional view of one of the belt cores prior to theapplicatib'n of a woven fabric cover. thereto;

Fig. 4 is a cross-sectional view of the core shown by Fig. 3 after ithas been turned inside out and moved about the pulleys shown by Fig. 2;

Fig. 5 is a fragmentary cross-sectional view illustrating a mold forvulcanizing V belts;

Fig. 6 is a fragmentary view of a finished V belt, with parts brokenaway, illustrating the construction thereof; and

Figs. 7 and 8 are views similar to Fig. 6, but pertaining to V belts ofslightly different constructions.

The present application is a division of application Serial Number454,596, filed May 22, 1930, which is for the belt itself.

Referring to Fig. 1, an apparatus for assembling strips of material intoan annular band comprises a collapsible drum 10 supported on a shaft 11which is journaled in a bearing 12 forming part of a frame 13. A drivenchain 14 trained about a sprocket wheel 15 on the shaft 11 serves torotate the drum 10. Initially, a layer of unvulcanized rubber 16 (shownby Fig. 3) is wound about the drum 10 and thereafter a layer of bias cutwoven fabric 1'7 preferably rubberized, is wound about the rubber 16. Ina similar manner other strips of rubber 18, 19 and 20 and strips of biascut woven fabric 21 and 22 are alternately wound about the drum until aband of substantial thickness is'built upon the latter. Consequently theband thus formed comprises stfips ofbias cut woven fabric separated bythin layers of rubber. It should be understood that instead of applyingseparate strips of fabric to the drum, a single strip can be wound aboutthe drum until several convolutions have been built up. Also, the rubbermay be applied to the fabric only before assembling the band upon thedrum, thereby eliminating the winding of separate strips of rubber andfabric.

Following the application of the layers of fabric and rubber to the drum10, a' cord 23 is applied to the band of material thus assembled on thedrum. Initially, the cord 23 is impregnated with rubber cement or thelike by passing it through a vessel 24 containing such material inliquid form. Then the cord is conducted through a conventional dryingapparatus 25 for the purpose of drying the cement prior to itsapplication to the drum 10. It should be under stood that the dryingapparatus" may be of any suitable construction and ordinarily itcomprises a heated housing and means for causing a blast of air to bedirected upon the cord as it passes through such housing. After the cordpasses through the drying apparatus 25 it is conducted under a pulley 26journaled in a standard 27 and then over a pulley 28 journaled in thestandard and through an aperture 30 of an arm 29 secured to the standardadjacent the last mentioned pulley 28. Then the cord is directed throughan aperture 33 of an arm 31 secured to a cross-head 32 which is slidablymounted upon guide rods 34 and 35 extending between the frame 13 and astandard 3'7. After passing through the aperture 33 the cord is directedabout a pulley 36 on the cross-head 32 and then applied helically to thedrum 10, by moving the cross-head 32 longitudinally of the guide rods 34and 35 and simultaneously rotating the drum. Then a sheet of rubber 38is wound over the convolutions of cord 23, which assists in retainingthe cord in proper position. The annular band of rubber, woven fabricand cord 'now assembled, then is cut into a plurality of narrow annularcores 45 (Figs. 3 and 4) by means of a knife 39 adapted to be projectedthrough slots 40 in a bar 41 projecting from one'side of the frame 13 inparallel relation to the drum 10. Following the cutting of the band intonarrow annular cores, the drum 10 is collapsed and the strips areremoved from the latter.

A woven fabric envelope 46 then is applied to each of the cores 45. bymeans of an apparatus shown by Fig. 2. This apparatus is identical tothat disclosed in the patent to Burkley et a1 1,747,856, and,consequently, need not be explained in detail. Essentially, it comprisesa plurality of pulleys 42, 43 and 44 which are adapted to support eachof the cores 45 during the application of a woven fabric cover thereto.Pulleys 42 and 44 are mounted upon a movable arm 47 in order that thecore 45 may be positioned upon the pulley 43 and removed therefrom. Adriven disc 48 contacts with that portion of the core extending betweenthe pulleys 42 and 44 and serves to rotate the core and stitch the cover46 to its outer peripheral surface. The cover 46 is directed between thedisc 48 and core 45 and edge portions of the cover" are stitched to thesides of the core by folding devices 49 disposed at opposite sides ofthe core. Then the edge portions of the cover 46 are fold ed about theinner peripheral surface of the core by means of folding devices 50 and51.

If the layers of woven fabric 17, 21 and 22 and the rubber 16, 18, 19and 20 are applied to the drum 10 prior to the cord 23, the core 45 maybe turned inside out before the woven fabric cover 46 is appliedthereto. This may be desirable because the core 45 is passing around thepulleys 42, 43 and 44 is subjected to forces which tend to widen theinner peripheral portion thereof and the covered core would have aninner peripheral surface wider than its outer peripheral surface. In thefinished V belt it is the inner peripheral surface that is narrowest,and by turning the core inside out before applying the cover 46, theouter peripheral portion of the finished belt is the portion widened asshown by Fig. 4, by reason of contacting with the pulleys 42, 43 and 44.It should be understood that after the cover 46 is applied to the core45, the assembly again is turned inside out or reverted to its originalcondition. When thus reverted to its original position. the outer'peripheral surface of the core is widest as shown by Fig. 4 and,consequently, the core may be readily disposed in a V-shape groove 55 ofa vulcanizing apparatus 56 shown by Fig. 5. It is evident that if theinner peripheral surface of the core were widest, the core could notreadily be disposed properly in the groove 55 of the vulcanizingapparatus and probably some distortion of the core in a lateraldirection would occur before it could be finally vulcanized to V-shape.A belt of the type described is shown in its finished form, by Fig. 6.

As an alternative method of manufacturing V-belts such as thosedescribed, the core shown by Fig. 3 in cross-section may be assembledupon the drum 10 in a reverse manner. That is, first the cord 23 andrubber normally on the outer surface of the core may be wound about thedrum 10 and then the several layers of fabric and rubber may be woundabout the cord. Cores manufactured from a band of material thusassembled need not be turned inside out before the cover is applied, butit is necessary to turn the core inside out after the cover is applied,in order that the component parts of thefinished belt will be disposedin their operative positions.

The construction of V belts shown by Fig. 7 is slightly different fromthat shown by Fig. 6 in that a layer of fabric 60 is disposed adjacentand inward of the cord 23 and comprises loosely woven threads extendingpreferably obliquely to the length of the belt. This construction lendsan advantage to the belt because rubber can be easily forced through theinterstices of the fabric and thereby better adhesion may be securedbetween the cords and the other layers of fabric. Moreover, the looselywoven fabric 60 does not materially weaken the connection of rubberbetween the cords 23 and fabric 21, although it does provide a basewhich maintains the cords aligned transversely of the belt.

{The construction shown by Fig. 8 is similar to that shown by Fig. 6,but instead of using closely woven fabric as shown in the latter figure,the fabric employed is the same as that utilized in the constructionshown by Fig. '7 and indicated at 60. It will be noted that the innerportion of the belt shown by Fig. 8 prac tically constitutes a body ofrubber because the interstices in the fabric are very large. Hence, theprobability of separation of component parts of the inner portion of thebelt is practically obviated, while at the same time a very secureadhesion is provided between the cord and the inner portion of the belt.Moreover, the inner portion of the belt shown by Fig. 8 is relativleysoft and flexible, which obviates hard or rigid corners at-the sides ofthe inner peripheral surface of the belt and thereby prevents to a greatdegree, breaking of the cover of the belt at such corners. I

In all of the constructions illustrated, it will be noted that anendless cord 23 constitutes the load transmitting part of the belt, andthat there are no laps in such part of the belt that may becomeseparated. Furthermore, the convolu- ''tions of the cord are disposed ina plane, parallel to the axis about which the belt operates. In suchconstructions, the convolutions of the cord define the neutral plane ofthe belt and since such convolutions are'all located in such plane,separation of parts of the tensile layer by reason of differences instresses at opposite sides of the neutral plane is prevented.Manifestly, if

the layer of cords is provided with rubber at opposite sides thereof,such rubber will naturally withstand tensile and compressive stresses,and it will not separate from the cords because immediately adjacent thelatter the stresses are practically negligible. In the constructionsillustrated particularly by Fig. 8, the possibility of internal stressesin the belt separating any portions thereof is practically obviated,because the layer of cords is at therneutral plane, and the material onopposite sides of the cords in effect operate similarly to elasticrubber even though fabric comprises a part thereof, because such fabricis loosely woven and the rubber projects through the intersticesthereof.

Actual operation of V belts such as provided by this invention indicatesthat the life of the belt is increased to a marked degree. Experimentshave determined that belts constructed according to prior practices havea life approximately one-third as long as that of belts constructedaccording to this invention. A primary reason for this increase in thelife of V belts resides in locating the tensile members only at theneutral plane of the belt instead of providing tensile members on'oneside of the neutral plane which would be subjected to compressivestresses. Moreover, on opposite sides of the neutral plane, apractically integral rubber construction is provided, even though fabricis employed, which prolongs the life of the belt because rubber isparticularly adapted to withstand the stresses set up in the belt. Whilea single layer of tensile cords is preferred, it is to be understoodthat conditions may warrant the employment of more than a single layerof helically arranged tensile cords and that such variations inconstruction are within the contemplation of the invention. I

Although only the preferred forms of the invention have been shown anddescribed in detail, it will be apparent to those skilled in the artthat the invention is not so limited but that various modifications maybe made therein without departing from the spirit of the invention orfrom the scope of the appended claims.

What we claim is:

l. The method of manufacturing endless belts which comprises winding 9.sheet of vulcanizable material about rotatable supporting means, windinga cord helically about the sheet, cutting the assembly into narrowannular cores, turn finally vulcanizing each assembly.

2. The method of manufacturing endless belts which comprises building anannular vulcanizable core, applying a woven fabric cover to the core,turning-the core inside out, and finally vulcanizing the assembly.

3. The method of manufacturing endless belts which comprises building anannular vulcanizable'core, moving such core about means engaging it atperipherally spaced points, applying a woven fabric cover to the core asit is moved, turning the core inside out, and finally vulcanizing theassembly to V shape in cross-section.

4. The method of manufacturing endless belts which comprises windingrubber and woven fabric having relatively large interstices aboutrotatable supporting means, winding a cord helically over the firstmentioned strips, winding a strip of vulcanizable materialover theconvolutions of cord, cutting'the assembly into narrow annular cores,and finally vulcanizing each of the latter.

5. The method of manufacturing endless belts which comprises windingsoft, vulcanizable ma- 5 terial about rotatable supporting means,winding a cord helically about the aforesaid material, applyingvulcanizable material about the convolutions of cord, cutting theassembled band

